Main aspects of constructing snow foundations for the new buildings of the Russian Vostok Station, East Antarctica

The present buildings of the Russian station Vostok (East Antarctica) began to operate in 1963 and have been under snow for many years. In connection with the extensive plans to study the subglacial Lake Vostok, it was decided to build a new wintering complex. Since there is a thick snow-firn layer in the construction area, the building of the complex requires solid foundations measuring 200×120 m. It was decided to build them by means of layer-by-layer snow compaction. Based on the approximate weight of the complex of 2500 tons, its operation time of about 30 years, and the estimated pressure of the station supports on the snow cover of 100 kPa, the foundations slab must have a density of at least 550 kg/m³, and the hardness of the coating of more than 0.5 MPa. In developing the methodology of constructing the slab for the new wintering complex, the method of layer-by-layer snow compaction was taken as the basis, developed for the construction of airfields on deep snow and suitable for taking heavy aircraft on wheeled landing gear. Experimental snow compaction was carried out using various caterpillar tracks, after which stamp tests of snow surfaces with different initial snow characteristics were performed. The bearing capacity of the foundations was assessed by calculating the vertical mechanical stresses on their lower surface, which are formed by the pressure of the station supports. The strength characteristics of the snow were assessed by direct measurements using the Brinell method and with the help of a mechanical press based on the samples taken and a penetrometer. Ultimately, the density of the snow layers in the upper part of the foundations reached 650 kg/m³. In addition to the base layer, 9 additional layers were formed. The first eight were formed in the summer of 2019/20, and the last one in January 2022. The total thickness of the foundations exceeded 3 metres. Upon their construction, the average surface excess relative to the natural snow cover was 210 cm. Based on the rate of snow accumulation, as well as the subsidence of the station supports and foundations into the snow mass, the foundations surface will equal the level of natural snow cover in approximately 30 years.